International practice has influenced a change in the way risk is assessed for the transportation of Dangerous Goods (DG) in specific scenarios.
Austroads has proposed a new approach for assessing whether the risk resulting from the transit of DG is lower on a tunnel route or lower on an alternative surface route.
The approach, according to Austroads, largely draws on European experience where countries like Austria, Germany, France, Italy, the Netherlands, Spain and Switzerland have national methodologies that offer an official evaluation procedure. Prior to the release of this Austroads methodology no such national method existed in Australia or New Zealand.
Austroads said the decision to restrict DG traffic through tunnels should also consider environmental and ecological risks, with community, social and economic benefits.
“Neither Australia nor New Zealand have a standardised risk assessment approach for considering risk to life associated with how we route dangerous goods,” said Austroads Transport Infrastructure Program Manager, Ross Guppy.
“By providing this method, we address a need of road authorities to have a rational documented risk-based input to the multi-facetted decisions that must be made about routing dangerous goods through tunnels.”
The Australasian approach is based on a Dangerous Goods Quantitative Risk Assessment Model (DG-QRAM) – an internationally applied software jointly developed by PIARC (World Road Association) and the Organisation for Economic Co-operation and Development (OECD).
“One of the main advantages of DG-QRAM is the ability to estimate the risk of dangerous goods transport through both a tunnel and an alternative open-air route, enabling a comparative risk assessment to inform route evaluations and regulatory decisions,” said Guppy.
The application of the methodology in the Australasian context is demonstrated in a case study of a hypothetical tunnel, illustrating the stages of the comparative assessment, with incorporation of risk mitigation measures.
The DG risk assessment guidance is provided as a series of three reports that should be read and applied together.
The report reviews best international practice in road tunnel dangerous goods risk assessment. It provides justification for the selection of DG-QRAM as the tool most appropriate for comparative risk assessments and identified adjustments that should be considered to reflect the Australasian context.
The report provides background on the development, capabilities and limitations of the DG-QRAM tool as well as guidance as to how it should be applied to road tunnels in Australia and New Zealand.
The case study illustrates the stages of the comparative assessment, with incorporation of mitigation measures. It is intended that transport authorities, competent authorities and risk specialists will find the case study a useful demonstration of the intent of the method that is detailed in the manual.